1. Field of the Invention
The invention relates to an abnormality detection apparatus for a power supply circuit associated with a control apparatus for an internal combustion engine. More particularly, the invention relates to an abnormality detection apparatus that detects an abnormality in a power supply circuit having, as a power supply, a chargeable/dischargeable battery connected to a power generator and a load, and an internal combustion engine control apparatus that performs automatic stop/start control of an engine installed in a vehicle, that is, stops the engine when a predetermined condition is met, and restarts the engine when the condition is unmet after being met.
2. Description of the Related Art
An automatic stop/start control apparatus for an internal combustion engine is proposed (in e.g., Japanese Utility Model Application Laid-Open No. SHO 63-65833) which has a battery sensor for detecting an abnormality of a battery. When the battery sensor detects an abnormality of the battery, the apparatus prohibits the automatic stop/start control of the internal combustion engine so as to prevent an automatic stop of the operation of the engine.
In some cases, however, this type of control apparatus fails to automatically restart the internal combustion engine. For example, if there is a contact failure in a power supply circuit that includes the battery, electric power is not supplied to a self-starting motor for starting the internal combustion engine even though the battery sensor does not detect an abnormality of the battery. Therefore, once the engine is automatically stopped with such an undetected power supply circuit failure, the engine cannot be automatically restarted.